This application seeks funds for continuation of Grant HL-18947-02 entitled "Indirect Mean Blood Pressure in Animals". The research completed to date has demonstrated that indirect mean blood pressure can be obtained with routine success in normo, hyper and hypotensive, anesthetized and unanesthetized ponies and horses using the oscillometric method. The oscillometric method employs the point of maximal oscillations in cuff pressure as the indicator of mean arterial pressure. The present application requests funds to develop the method for application to beef animals (calf and cow) and to smaller domestic animals, such as the dog, sheep, goat, etc. These species are important both in veterinary medicine and are used as animal models in cardiovascular research. In this research we will develop the criteria for the accurate determination of indirect mean blood pressurein these animals. We will also identify the limits of accuracy attainable, both in terms of the range of blood pressure and the error encountered with use of the incorrect size of member-encircling cuff. In addition, we will continue research on our theoretical model which identifies the factors which govern the accuracy of the method. Finally, we will investigate the ability of the oscillometric method to indicate systollic and diastollic pressures as well.